NISTM June 27, 2013 Tank Conference

Anaheim, California PEMY Consulting

Philip Myers 925-302-6707

Phil@PEMYconsulting.com

Fixed Roof Tank Over Pressure Incident

• An unexpected high flow rate of nitrogen surged into the tank at the arrival of the first pipeline displacement pig, causing the frangible roof seam on the Tank to part. Damage occurred on the tank roof, sidewall and tank stairway landing.

2

Lightning Strike Tank Seal Fire

• A tank rim-seal fire was started when a 160,000 barrel open floating roof tank in gasoline service was struck by lightning. At the time of the incident, the tank was approximately ¾ full and had been undisturbed for approximately 3 weeks. The tank roof seals consist of a primary mechanical shoe seal and a secondary metallic wiper seal, which were installed in late 2000 when the tank was in diesel service. In 2004 the tank was converted to gasoline service. The seals were originally installed to minimize the amount of rainwater getting into the tank.

3

4

What went wrong

• The urethane that was used for the primary shoe seal fabric is compatible with diesel, but is not compatible with the oxygenate blended into gasoline. The fabric deteriorated after the tank was converted to gasoline service, which resulted in holes and tears in the fabric.

• No Management of Change was performed when the tank was switched to gasoline service, because the MOC process had not yet been implemented at this terminal location.

• The lightning shunts were not being inspected as part of preventative maintenance at this terminal, and some of them were discovered afterwards to not be in contact with the tank shell.

Lightning Strike Tank Seal Fire

5

Lessons Learned

Compatibility of primary shoe seal fabrics with stored products is not widely recognized among the terminal workforce. To

maintain this learning, an item related to this incident, including Lessons Learned, has been added to the Terminal and

Operations Engineering SharePoint site.

This incident helps to reinforce the importance of the MOC process, which is now in place at this location.

Visual inspection of lightning shunts has been added to the monthly tank inspection checklist.

Example of lightning shunt not

contacting shell of tank

Floating Roof Collapse and LOC

6

7

What went wrong

• The tank was isolated three months prior to the spill incident, which included closing and locking the roof drain valve.

• Almost no inspection of the roof was being performed by terminal workers, despite frequent rainfall in the area. Excessive water accumulation on the roof caused the landing legs to collapse.

• The contract Entry Supervisor reported an excessive amount of water on the tank roof shortly after he ordered his worker out of the tank; however, no corrective actions were taken.

Floating Roof Collapse and LOC

8

Lessons Learned

Always perform frequent inspections of EFR tanks, whether in-service or out-of-service, in

order to determine, among other things, liquid accumulation on the roof and to drain the

roof when necessary.

Always conduct inspection of EFR tanks following rain storms to help ensure that the roof

is drained of accumulated water arising from the rain fall.

Always conduct pre-job planning and risk assessment as the first step in the equipment

isolation process and in the preparation of the Isolation Checklist, and always ensure that

Terminal Management approves the isolation plan before implementing.

Senior and more experienced facility personnel must always take ownership for ensuring

that critical reviews are conducted on all plans that can affect the safety of the facility in

which they work, and always exercise Stop Work Authority where there is doubt regarding

the adequacy of such plans, irrespective of the perceived level of final authorization.

Always address abnormal conditions and take deliberate steps to respond to safety

concerns in order to ensure that risks created by the presence of a potential hazard

are assessed to help prevent possible losses.

9

How Do You Assess Risks?

• Guesses, hunches,arm-waiving, or just keeping the blinders on are not uncommon, but there are better ways…

10

What is Risk?

• Risk is the combination of:

– the likelihood of a failure (LOF) that causes a loss, and

– the consequence of that failure (COF)

• Risk = LOF x COF

11

Risk Assessment and Management

• Risk can be assessed by determining:

– What can go wrong

– How likely is it to happen, and

– What would be the consequences

• Risk can then be managed by instituting strategies to reduce the risk

12

Details of Consequence Analysis

• Above ground release scenario:

– Release volume: flow rate and duration.

– Flow rate: overfill rate or hole size.

– Also account for dike containment and distance to offsite receptors.

offsite dike / liner

surface water

13

AST Consequence Analysis Overview of Leak Scenarios

surface water

1 2 3

6

ground water

offsite dike / liner

1

2

3

4

5

6

dike/liner

onsite, surficial soil

offsite, surficial soil

subsurface soil

groundwater

surface water

Cleanup Location

4

5

14

Details of Consequence Analysis

• Below Ground Releases –first, estimate time

required to reach groundwater depth

–then, if release duration results in contact, estimate portion in water

ground water

dike / liner

0

5

10

0

5000

100000

200

400

600

800

200

300

400

500

600

700

19

The Decision Problem

• Which control technique should be selected for this AST: – Prevention?

– Detection?

– Protection?

Note: Remediation is not an acceptable control measure

The Big Picture = Management Systems

• Local, State, and Federal Regulations and Rules

• Corporate Management Systems

• Industry and API standards

• Experts and Consultants

• State of the Art Ideas: risk assessment, fitness for service, risk based inspection, etc

Features of a Management System

• MS is a business function of the overall organization.

• MS is a systematic and organized approach to solving safety and environmental problems.

• The purpose of a MS is to achieve and maintain the necessary level of safety and environmental in an organization.

• Implementation of a MS involves management organization, responsibility, and competence (‘human issues’).

SMS Key Elements

• Key Element 1: Safety and Environmental Advocacy • Key Element 2: Safety and Environmental Information • Key Element 3: Hazard and Risk Assessment and Analysis • Key Element 4: Management of Change • Key Element 5: Procedures and Safe Work Practices • Key Element 6: Training • Key Element 7: Equipment Integrity and Industry Standards • Key Element 8: A Permit System • Key Element 9: Pre start up safety review • Key Element 10: Emergency response and control • Key Element 11: Near Miss and Incident investigation • Key Element 12: Auditing • Key Element 13: Documents and Data Information Management Systems

More Information on Management Systems

• PEMY Consulting (phil@pemyconsulting.com) • API RP 75 Development of a Safety and Environmental

Management Program for Offshore Operations and Facilities

• API RP 75L Guidance document for the Development of a Safety and Environmental Management System for Onshore Oil and Natural Gas Production Operation and Associated Activities

• API 770 A Manager’s Guide to Reducing Human Errors – Improving Performance in the Process Industries

• API 754 Process Safety Performance Indicators for the Refining and Petrochemical industries

• UK Health Safety Executive Web Site

API Tools

• API 2610 – petroleum terminals

• API 340-PUB 340 summarizes 99 causes of liquid releases at AST facilities and presents 176 measures to prevent or control them.

• API 653 – tank inspection

• API 2611 – piping inspection for terminals

• etcera

API 2610

40

Types of Storage Tank Floating Roofs

41

Container

Type

Atmospheric

Tank

Low Pressure

Tank

Pressure

Vessel

Shell:

Horizontal

Shell:

Vertical

Tank has:

Open Top

Tank has:

Fixed Cover

Shell:

Sphere

Shell:

Vertical

Shell:

Noded Spheroid

Shell:

Vertical

Shell:

Sphere

Shell:

Horizontal

(“Bullet”)

Top Closure:

Flat

Hemispherical

Dome

Bottom Closure:

Flat

Hemispherical

Tank Taxonomy

Top

Bottom

Closure:

Flat

Hemispherical

Closure: N/A

Closure: N/A

Closure: N/A

Roof Types:

Aluminum Domes

Support Cone

Self Supported Cone

Umbrella Roof

Steel Dome

Other

Bottom Types:

Single bottom with RPB (HDPE)

Single bottom with no RPB

Double Bottom

Other, such as elevated onto grillage

Top Closure:

Cone

Dome

Hemispherical

Bottom Closure:

Cone

Hemispherical

Shell is:

Aboveground

Buried

Partially Buried

Shell is:

Anchored

Unanchored

Tank Shell Joint Construction:

Single Lap Welded

Double Lap Welded

Full Fusion Butt Welded

Riveted

Riveted Welded

Double wall or tanks with integral secondary containment

Floating Roof Type:

Double Deck

Steel Annular Pontoon

External Pan Roof

Other

None (special case for nonvolatile products)

Floating Roof Type:

Double Deck

Steel Annular Pontoon

Pan or Bulkheaded Roof

Aluminum Skin & Pontoon

Aluminum Honeycomb

Composite

Other

None / tank has insert gas blanketing

None

Note:

Floating roofs designed for open top tanks have

different design parameters than for covered or

fixed roof tanks. The floating roofs in open top

tanks which are later retrofitted with covers then

become a “covered external ---“

Top Closure:

Flat

Hemispherical

Shell is:

Anchored

Unanchored

42

Types of Storage Tank Fixed Roofs

43

Sources of Potential Releases at AST Facilities

• Aboveground storage tanks

• Piping systems

• Loading areas

• Ancillary equipment

• Operating systems

• overfills

M M

Sources of Potential Releases at AST

Facilities

Ancillary Equipment

Operator

Error

Unloading AreasPiping

Loading Area

Release

AST

Vapor emissions

Shell

Bottom leaksMarine or pipeline receipts

Aboveground

Storage

Tank

Secondary

Containment Dike

Dike

LinerRelease Prevention Barrier:

Double Bottom w/

Synthetic Liner

& CP

Protection Control Measures

Figure 5

Dike Liner:

Geosynthetic

"Claymax"

Overfill

Shell

Bottom

Example Focus Area - Secondary Containment

• The ultimate insurance policy

• Historical

• Regulatory

• Most are never used

• Lack of standardization

• Proof testing

• Leaks

Marsh Risk Engienering Position Paper 01

SW Florida power plant- 80,000 gallon overfill

Buncefield fuel depot

Before Dec 11 2005

Buncefield fuel depot

Dec 11 2005 (a Sunday)

Many tanks connected by manifold.

Historical legacy - Newport

Numerous Unstandardized Methods of Design and Construction

• A dirt pond

• A flat earthen area with a concrete dike surrounding it

• Fully concreted basis or resevoir

• A tank within a tank

• A large pan

Secondary Containment

• No proof testing normally done; cannot be easily tested so we don’t know if it will really work

• But its not rocket science so qualified principles using qualified designs can reduce the risk

• Some principles: – Hydraulic pressure and tightness – Radian heat loads on joints and penetrations – Nature of underlying soil – Speed with which contents could permeate soil – Pros and cons of liners (lines can make things worse or distort the overall risk

picture) – Bouyancy effects for either spills or major storms/floods

• API 653 does not address secondary containment inspection

Lessons from Buncefield

• Any concrete structure for retention of liquids should be designed to minimise the risk of cracks forming. If cracks do form they should be adequately repaired.

Leak Through Rebar Holes

Good Practices for Penetrations

Good Practices for Joints

Good Practices for New Joints

Lining Secondary Containment

• Not normally used but regulatory pressure being applied

• Pros and Cons Not Clearcontroversial topic

• API 341 covers this in detail

API 341 Results

• Vehicular traffic and daily operations cause damage • Material failures from uv radiation where exposed,

chemical reactions with soil, freeze cycles, loss of plasticizers, embrittlement with time

• Failures at penetrations and around structures • Subgrade failures due to settlement, liner movement stress

failures • API conclusion is that liner effectiveness is limited. • From a risk mitigation perspective, in most but not all

cases, the resources used for liners would be far better allocated to things like API inspections, better design and construction, management systems, overfill protection, etc (PEMY opinion)

7/18/2013 THH\AST\FSS2002.PPT 68

7/18/2013 THH\AST\FSS2002.PPT 69

7/18/2013 THH\AST\FSS2002.PPT 70

7/18/2013 THH\AST\FSS2002.PPT 71

7/18/2013 THH\AST\FSS2002.PPT 72

Option 1 Geomembrane

7/18/2013 THH\AST\FSS2002.PPT 73

Option 2 Geosynthetic Clay Liner

Some Other Ways To Use Secondary Containment

• Severe settlement (+)

• Overfills (-)

• Seismic (-)

• Corrosion (+)

• Operational (-)

• Vandalism or Terrorism (-)

• And more (?)

Purpose of Foundations

• Support tank (obviously)

• Minimize corrosion

• Allow internal (and external drainage)

• Prevent many different modes of settlement (differential, out of plane, edge, etc)

• Allowance for future settlement

• Provide anchorage for pressure tanks or for seismic

Common Foundation Types

• Earthen

• Slab

• Crushed Stone Ringwall

• Concrete Ringwall

• Piled

• Others

Tank Size

• Large Tanks (50 feet in diameter or greater) – use concrete ringwall (preferred)

• Small Tanks (20 feet in diameter or less) – use concrete slab foundation (preferred).

• Medium Tanks (20 to 50 feet in diameter) can be classified as either large or small at the discretion of the foundation designer and tank design engineer, for the purpose of choosing the type of foundations only.

Caveat

• Do not just put a tank on a foundation (this is done all too often)

• Get a geotechnical engineering firm to assess and determine the soil and subsurface conditions

• Get a recommendation from them on the foundation type (but you will have to provide the criteria for acceptance)

• Make sure you consider RPBs

Soil Type

• In some instances, large fixed roof tanks can be supported directly on properly prepared good native material. Choose this method only if recommended by the soils consultant. Pile supported concrete slab foundations are used for tanks on poor soils, regardless of the tank size

Leak Detection Groove Patterns

Settlement Data Real Tank

0 2 4 6 8 10 12 14 16 18 200.75

0.76

0.77

0.78

0.79

0.8

0.81

Best Fit Cosine Curve

0 2 4 6 8 10 12 14 16 18 200.75

0.76

0.77

0.78

0.79

0.8

0.81

mse1 = 8.5875e-05

0 2 4 6 8 10 12 14 16 18 200.75

0.76

0.77

0.78

0.79

0.8

0.81

mse2 = 4.1506e-05

Best Fit Cosine Curve

-1 -0.50 0.5 1

-1-0.500.51

0.75

0.76

0.77

0.78

0.79

0.8

0.81

Second Mode Fit

-1

-0.5

0

0.5

1

-1

-0.5

0

0.5

10.74

0.76

0.78

0.8

0.82

Better “view”

-1-0.5

00.5

1

-1-0.5

00.5

1

0.75

0.76

0.77

0.78

0.79

0.8

0.81

0.82

Better View Both Modes Shown

-1-0.5

00.5

1

-1-0.5

00.5

1

0.75

0.76

0.77

0.78

0.79

0.8

0.81

0.82

Residuals

0 1 2 3 4 5 6 7-1

-0.5

0

0.5

1

0 1 2 3 4 5 6 7-1

-0.5

0

0.5

1

Elephant Foot Buckle

Tanques de Gasolinas (41, 40, 32) (MOGAS TKS)

Tanque de almacenamiento (Diesel-22)

BULLETS LPG (FUERA DE SERVICIO)(MOTHBALLED LPG BULLETS SANK AT ONE SIDE)

TANQUE 10 DAÑADO (FUEL OIL)

Thank You

For more information contact

Phil Myers

phil@pemyconsulting.com